Abstract: A fusion polypeptide comprising, as at least part of the N-terminal portion thereof, an N-terminal portion of HSA or a variant thereof and, as at least part of the C-terminal portion thereof, another polypeptide except that, when the said N-terminal portion of HSA is the 1-n portion where n is 369 to 419 or a variant thereof then the said polypeptide is one of various specified entities.The HSA-like portion may have additional N-terminal residues, such as secretion leader sequences (signal sequences). The C-terminal portion is preferably the amino terminal fragment of human urokinase-type plasminogen activator. The N-terminal and C-terminal portions may be cleavable to yield the isolated C-terminal portion, with the N-terminal portion having served to facilitate secretion from the host. Such cleavage can be achieved in yeast using a sequence cleavable by the KEX2 protease of S. cerevisiae.

Abstract: A process for the preparation of albumin which has extremely low levels of or is essentially free of colorants, metal ions, human proteins, fragments of albumin, polymers or aggregates of albumin, and viruses, and which is relatively non-glycated, relatively high in free thiol and with an intact C-terminus. The process comprises passing albumin (preferably expressed and secreted by transformed yeast) through two chromatography purifications, ultrafiltering the product, passing through two further chromatography steps and again ultrafiltering the product.

Abstract: A yeast promoter comprising the promoter of the (cytoplasmically located glycerol-3-phosphate dehydrogenase gene (GPD 1) possesses advantageous capacity to regulate the expression of heterologous polypeptides in yeasts transformed therewith. Expression of such polypeptides utilizing the GPD1 promoter can be regulated by the presence(repressed) or absence(derepressed) of high levels of sucrose or glucose in the fermentation medium. Alternatively, a non-repressing carbon source, such as glycerol or ethanol, can be added to the fermentation medium.

Abstract: Secretory leader sequences, for use in secreting heterologous polypeptides in yeast, are formed by fusing part of the human serum albumin pre-sequence or part of the Kluyveromyces lactis killer toxin pre-sequence to the Saccharomyces cerevisiae mating factor alpha-1 KEX2 cleavage recognition site. The resulting fusion leader sequences are:(a) H.sub.2 N-Met-Lys-Trp-Val-Ser-Phe-Ile-Ser-Leu-Leu-Phe-Leu-Phe-Ser-Ser-Ala-Tyr-Ser- Arg-Ser-Leu-Asp-Lys-Arg-COOH or(b) H.sub.2 N-Met-Asn-Ile-Phe-Tyr-Ile-Phe-Leu-Phe-Leu-Leu-Ser-Phe-Val-Gln-Gly-Ser-Leu- Asp-Lys-Arg-COOHConservative variations are also encompassed.